PARIS (AP) — Europe’s privacy watchdogs are demanding details on the extent of U.S. surveillance efforts in the wake of NSA leaker Edward Snowden’s revelations about the PRISM spying program.

The National Security Agency’s PRISM operation compels major Internet firms to hand over detailed contents of communications such as emails, video chats and more.

The G29, an umbrella organization that includes data protection agencies across Europe, said Monday it wrote EU Justice Commissioner Viviane Reding last week to demand “specifics regarding the exact nature of the data collected” by PRISM, and details on how U.S. authorities access Europeans’ data and the recourse EU citizens have.

In its statement, the G29 says it wants the information on PRISM from Reding so that it can “evaluate in an independent manner the potential violations of European law and data protections, as well as the consequences of PRISM for the protection of European citizens’ private lives and data.”

The G29 also intends to investigate whether PRISM-like spying programs are being run by any European countries.

Last month justice ministers from Germany and France signed a joint declaration in which they agreed to establish “adequate safeguards” for EU citizens’ data that will balance freedom and the need for security.